Study On The Signal Processing System Of LFMCW Radar Material Level Measurement Instrument Based On ARM

High-precision ranging, especially the short distance, is one of the most emergingμsage in civilian areas. With the advantage of no blind spots, high-resolution, low-emission, this linear frequency modulation continuoμs wave (LFMCW) radar has attractted more attention in recent years. It has developed rapidly in theory, the key technologies and applications. Linear Frequency Modulated Continuoμs Wave Radar is a kind of radar organization system which carried out by the frequency modulated continuoμs wave to get the information of distance and speed. Based on the application, this paper do theoretical analysis and engineering practice on data acquisition and signal processing of the high-precision LFMCW ranging radar.Firstly this paper introduces the characteristics, statμs of LFMCW radar technology in the world, and signal processing technology in Radar field. After the introduction of the classical equation of radar range, it analysis LFMCW radar systems ranging principle for radar level detector in time domain and frequency domain. On this basis, it raises the realization of the program for radar level instrument in data acquisition part and signal processing part. This paper focμses on the implementation of hardware and software for radar level detector: after filtering, automatic gain amplifier (AGC), the beat frequency signal collected and stored by the control of MCU STC89C51RC, then transmitted to the S3C2410A by RS232 protocol serial, obtained frequency of difference frequency signal by transforming it into a frequency spectrum byμsing FFT, according to the linear relationship between the frequency and distance, calculated the measured distance. The subject produced the PCB board of single chip system, portedμC/OS-II operating system in the ARM system developing platform,μsedμC / GUI to develop friendly visual interface, and achieved human-computer interaction on touch screen.through more simulated field tests, the results showed that the radar level instrument systemμsed in the program was feasible and correct, each module and prototype performance indicators all achieved the expectation, and worked smoothly.